Means for cooling air or oxygen enriched air within an enclosure



A. HEIDBR NK 2,550,810

May 1, 1951 J,

MEANS FOR COOLING AIR OR OXYGEN ENRICHED AIR WITHIN AN ENCLOSURE FiledFeb. 12, 1947 2 Sheets-Sheet l INVENTOR JAY A. HEwBmNK "WWW y 1951 J. A.HEIDBRINK 2,550,810

MEANS FOR COOLING AIR 0R OXYGEN ENRICHED AIR WITHIN AN ENCLOSURE FiledFeb. 12, 1947 2 Sheets-Sheet 2 Fl .3 /8 9 r l i n L L 8 T INVENTOR.

JAY A. HEIDBRKNK Patented May 1, 1951 UNITED STATES PATENT OFFICE MEANSFOR COOLING AIR OR OXYGEN ENRIOHED AIR WITHIN AN ENCLOSURE Jay A.Heidbrink, Minneapolis, Minn., 'assignor to Air Reduction Company,Incorporated, New York, N. Y., a corporation of New York ApplicationFebruary 12, 1947, Serial No. 728,034

I Claims.

1 My invention relates to a means for cooling air or oxygen enriched airwithin an enclosure whichis adapted tosurround a bed. In particular itrelates to means for cooling the atmosphere within an enclosure when theatmospheric temperature surrounding the enclosure is excessively high.On administering oxygen therapy to a patient it is essential that theair which surrounds the head of the patient should be enriched withoxygen and it should be cooled to a point below what is regarded asnormal room temperature, and should preferably be to about 65 F., as thelowered temperature tends to inhibit bacterial activity. The .particularadvantage of thepresent invention is that when the temperature of theair surrounding the enclosure is excessively warm, as for example nearor above 90 F., room temperature, the air mixture supplied to thepatient can be maintained at the desired lower temperature.

In the past, the generalipracticerelating to this subject matter was tointroduce cooled air through the side walls of the enclosure thatsurrounds the patient at a point spaced above the .pati'ents head and insuch a manner that the incoming air "was directed toward the walls ofthe enclosure so as to avoid a direct draft on the patients face. Inthis manner the cooled air initially carhe into contact with the Wallsof the enclosure from which it was deflected in a turbulent manner abovethe patients head. Under conditions of reasonably moderate temperaturesthe prior art arrangement was satisfactory, but difficulty arose whenthe temperature surrounding the enclosure became excessively high, forunder these conditions the cooled air absorbed so much heat from thewalls of the enclosure that it could not be maintained at the desiredlowered temperature. It was the practice when atmospheric temperatureswere high to increase the rate of air flow into the enclosure tocompensate for the gain in heat but this was not satisfactory because itcreated an intolerable draft on the patient and failed to keep the airproperly cooled.

thereon, and is constructed in such a manner as to "direct the flow ofcooled air in a quiescent manner with virt'ually'no turbulence in adownward direction and around the head of the person. Meansare alsoprovided for withdrawing the warmer air from within the top of theenclosure so as to create cyclic passage of air through the enclosure.

The principal value of the distributor is for diff-using the incomingair without turbulence and with a minimum absorption of heat. For thisreason, the connection between it and the air cooling apparatus is asshort as possible and is situated .principally within the enclosurewhere it will be subject to a cooler exterior temperature and will,therefore, absorb less heat. Furthermore, the distributor is carefullyheat insulated from the enclosure and is arranged in spaced relation tothe side walls to cause the cooled air leaving the distributor todescend in a central column within the enclosure until it reaches thesurface of the bed, after which it spreads out and ascends in the formof an annulus. Also the distributoris constructed with such large areaof discharge openings that the air leaves it at a reduced velocity andfree of turbulence. The cyclic travel of the air is brought about byheat transfer which occurs through the side walls of the enclosure sinceit 'is a natural tendency for air to rise when heated, and to "aid inthis action the means for withdrawing the air from within the enclosureis situated preferably to open adjacent its upper portion.

However, when the temperature of the atmosphere surrounding theenclosure, is not excessively high, and may for example be less thanabout F., the cyclic distribution of air, through the absence of a rapidtransfer of heat, will tend to create an excessively cooled conditionwithin the enclosure. Under these conditions, means are provided fordiverting the flow of incoming air from the distributor and directing itagainst the walls ofthe enclosure to create a turbulent condition and tobring the incoming air quickly into contact with the walls so as tocreate a more rapid transfer of heat and thus prevent the air within theenclosure from being excessively cooled. Thus the cooling within theenclosure is maintained substantially constant with considerablevariations of surrounding room temperature.

An object of my invention is to provide means for cooling the air withinan enclosure which is adapted to surround abed.

Another object is to provide means used in combination with airconditioning apparatus for cooling the atmosphere within an enclosure soas to maintain the air entering the enclosure cooled when theatmospheric temperature surrounding the enclosure is excessively high.

Another object is to provide in combination with an air conditioningapparatus, means for introducin cooled air into an enclosure which issubject to a relatively higher temperature on its exterior surface, insuch a manner as to form a central column of descending non-turbulentcooled air which is separated from the walls of the enclosure by anascending annulus of warm air.

Another object is to provide in combination with an air conditioningapparatus and an enclosure having an air distributing means therein, aconduit forming a short connection between the apparatus and thedistributing means for conducting the cooled air thereto, which issituated within the enclosure and subject to the temperature of theatmosphere within the enclosure.

Another object is to provide in combination with an enclosure having acool air conduit entering therein, means for distributing the cool airin said enclosure in a non-turbulent descending column.

Another object is to provide in combination with an air conditioningapparatus and an enclosure a first means of distributing cooled airwithin the enclosure when the temperature of the air surrounding theenclosure is relatively high, and a second means of distributing the airwithin the enclosure when the temperature of the air surrounding theenclosure is relatively moderate.

A further object is to provide in combination with oxygen therapyequipment a means of providing a therapeutic air within an enclosurewhich is adapted to surround the head of a person reclining on a bed byproviding means for diffusing the therapeutic air within the enclosurein a quiescent manner and wherein the diffuser is situated with relationto the side walls of the enclosure so as to provide a central column ofdescending cool air which when it comes into contact with the bed willspread out and rise by virtue of heat absorbed from the side walls, thebed, and the enclosure, and preferably be removed from a point adjacentthe top of the enclosure.

Other and further objects may become apparent from the followingdescription and claims and from the appended drawings in which:

Fig. l is a side elevation of the invention with some parts broken awayand others shown in cross-section;

Fig. 2 is a plan view taken on the lines 22 of Fig. 1 looking in thedirection of the arrows;

Fig. 3 is a side elevation of the structure shown in Fig. 1 as seen fromthe left side thereof.

Fig. 4 is a enlarged detailed view of a part of one of the conduitsshown in Fig. l; and

Fig. 5 is an enlarged detailed view of a portion of the supportingstructure shown in Fig. 1.

Referring now to the drawings, the invention will be described indetail.

Referring now to Fig. 1, reference numeral 8 indicates a bed, which ishere shown as ,a hospital bed over which is suspended a hood indicatedby the general reference numeral i0. Hood I0 is intended to bepositioned with relation to bed 8 so as to surround the head of apatient reclining thereon. Hood 58 has a top portion l2 which is oval inshape as shown in plan view in Fig. 2. About the lower edge of topportion 12 is a rim or beading it. Secured about outer periphery of topportion i2 above beading M by a drawstring I6, is a curtain I8. Curtainl8 may be formed of a transparent plastic. such as 4 Vinylite, andbecause it is relatively thin will readily transfer heat to its insidesurface. Situated in the under surface of the top portion I2 is an airdistributor 20 which has a plurality of small regularly spaced apertures22 on its lower surface as shown in Fig. 2. Distributor 2!! which is inthe form of a shallow pan is heat insulated from top portion 22 by alayer of insulation 24 and is secured to top portion l2 by a pluralityof fastening means 28 which extend through insulation 24. Distributor251 is provided with an enlarged aperture 28 at one end of its lowersurface which receives a metal end portion 30 of a conduit indicated bythe general reference numeral 32. The combined area of the apertures 22is greatly in excess of the area of inlet opening 28.

Conduit 32 is provided for supplying air to distributor 20 and is formedof a lower portion 34 having at one end thereof a flange 38 whichextends to an open branch 38. Portion 34, above branch 38 is connectedto portion 38 by a length of flexible corrugated rubber tube 30. As moreclearly shown in Fig. 4, branch 38 extends at right angles to portion 34and is provided with a damper d2 which is pivoted at ts and controlledby a manually operable lever 46.

Also situated within hood Hi, is a second conduit 5e formed of an elbow5! having a flanged end portion 52. Extending upwardly from elbow 5! isa flexible corrugated rubber tube 54 which is open at its top portionand which extends up wardly within hood H) adjacent curtain l8torminating at a point adjacent one side of dis-' tributor 28, asclearly shown in Figs. 1 and 2.

Indicated by general reference numeral 60 is an air conditioningapparatus which is used in combination with hood Iii to withdraw the airtherefrom and purify and cool the air before returning it to the hood.Apparatus 68 consists of a casing 82 which has extending from an upperside portion, a conduit 64 having a flanged portion 68 which is joinedby a plurality of fastenings to flanged portion 52 of elbow 5| on eitherside of an aperture extending through curtain I8. Conduit 64, withincasing 62, terminates in a container 68, which within its interior, isprovided with a portion N! that contains a quantity of soda lime. Aconduit 72 extends from the lower portion of container 68 and enters oneside of centrifugal pump 14, whose impeller 16, is controlled by a motor18 to withdraw the air from hood l0 through the connection previouslymentioned and drive the air through an outlet 80. The outlet 88 of pumpM is connected to a refrigeration evaporator 82 which contains a coolingcoil 84. Evaporator 82 has extending from its upper portion a shortconduit 86 having on its exterior end a flange 88 which is joined toflange 36 of conduit 32 through an aperture in curtain 18. A thermometer90 indicates the temperature of the air leaving evaporator 82 throughconduit 86 and will in general be indicative of the temperature of airpassing into hood in.

A cylinder 92 containing compressed, pure oxygen, supplies additionaloxygen to the circulated atmosphere through a control valve 94 and aconduit 98 which extends into connection between pump it and evaporator82.

In order to provide refrigeration for evaporator 82, a conventionalmotor-operated refrigeration compressor indicated by the generalreference numeral 9'! is connected by a conduit 98 to refrigeration coil84 to provide fluid refrigerant therefor. In place of the air-cooling.means.

'i'Od H6 and Slidably engages Slot I I0.

tween evaporator 82 and distributor 20. of its large area and the greatnumber of apertures 122 on its 'lower surface, the air enteringAs'shown'inFigs. 1, 3 and 5, hood It is supported by apparatus 60. Ashaft I which is mounted on one side of casing 62'has-adjacent its upperportion 'a pivot 102 on which is pivot ally mounted a hinged portion104. Hinged portion I I14 hasextending from one side a handle I06 bywhich portion Hi l-may be pivotally rotated on pivot Hi2. Extending inthe same plane as "handle 106 and "forming an angular part of portion 5I04 is an upper portion I08 which has on one side'thereof a slot l Illhaving'an upwardly extending terminal portion H2 at one end and'adownwardly extending terminal portion ifi'at the other end. Tubularportion [98 is adapted to receive one end'of a rod HG, which throughbrackets H8 supports hood I'll 'from itstop portion l'2. Apin I29is'po'sitioned on one end of Hood It is, under certain conditions,adapted to'be folded alongside of apparatus is and to accomplish this,rod 116 is lifted-at its outer end to disengage pin "I20 from theterminal portions H2 of slot Ht,

thereafter-rod I I6 may be moved outwardly permitting pin i-2E) toslidably move along slot i Ill until'it is'turned andengaged in aterminal portion IM of slot H0, whence hood Ii! will be folded in avertical position alongside of apparatusi'il).

Iii-operation, the invention performs in the following manner. With 'thehood is surrounding a portion of be'd8 so as to enclose the head andupper'part of the patient reclining thereon, it is necessary tocontinuously supply oxygenenriched air to the'hood which must be at atemperature lower than that surrounding the exteriorof the hood.

Assuming the temperature of the air surrounding hood Ill to be about 85to 90 F. or higher, damper 42 will be adjusted by handle "46 so as todirect the flow of air entirely into distributor 20. 'with apparatusfiflin operation, the air within hood -ifi willbe in continuous circulationthrough the various elements of apparatus 60, and cooled air will betransmitted through conduit 32 to distributor 20. It will be :noted'thatconduit 32 is positioned within heed ID and forms a relatively shortconnection bedistributorZil loses its velocity and descends into :hood[-0 without turbulence and with'no appre- "ciable "force. tributor :20is centrally disposed in hood ill in spaced relation to curtain i8 sothat the cool air As clearly shown in Fig. 2, dis

ature on the outer surface :of curtain i3 being relatively high, thecurtain will form a radiating surface and .as the air contacts thecurtain it will .absorbheat and rise in the form of an annulus adjacentthe curtain. As the warm air .rises rwithin hood l0 "it will bewithdrawn near the upper portion-of the hood through theupper open "endof rubber tube 5d. Thus the cooled airentering the hood is insulatedfrom the heat "being radiated from the curtain by the ascendingannulus-0f warmer air and because conduit Because I 32 is comparativelysh'ort in length and 'is situated within the hood the incoming airreaches the patient at a comparatively low temperature even though amuch higher temperature "exists in the area surrounding tth'eiihood.

The airentering apparatus 60 hasrits carbon dioxide content removed bythe soda lime in container 68 and its oxygen supply em'iched by pureoxygen from cylinder '92. The evaporator 82 cools and conditions the airbefore it is returned to conduit32.

When the "temperature of ambient air surrounding hood 18 .is within amore moderate range, 'asfor example in the range of under 85 R, :thenon-turbulent cycle previously disclosed will tendtocause the airsurrounding thegpatient to become excessively cooled because of theslower rate of heat transfer through ourtain I18. Under theseconditions, damper42 is moved to divert the now of air from distributor'20, through the branch opening 38 intothe area of hood Iii above thepatients body and in the direction of curtain [8. This will terminatethe thermal cycle and cause "a turbulent agitation of the air so thatall of the air within hood i0 is brought into contact'withcurtain [8 tocause a more rapid rate of heat transfer and thusv raise the temperaturewithin :hood ill and maintain it at a higher level.

If the temperature produced by distributing the air through distributor2!] is excessively low and the temperature resulting from distributingall of the air through branch 38 is excessively high, damper 12 may bepositioned at an intermediate position to distribute a'portion of theair through "distributor Zfi-and aportion through branch 38, so that'arange-of temperatures within hood it may be obtained by regulating theposition of damper 42.

The principal advantage of my invention is that a suitable loweredtemperature may be maintained within an enclosure when the exteriortemperature is very high by providing for the cooled incoming air todescend in a nonturbulent central core within the enclosure in such amanner thatlthe central core is insulated from the walls of theenclosure by a rising annulus of warmer air. On the other hand, when theambient temperature is in a more moderate range, the air within theenclosure may be agitated in 'varying'degrees to prevent it frombecoming excessively cooled.

Another advantage is that by providing a relatively short connectionbetween the air-cooling means and the distributor, which connection issituated substantially entirely within the enclosure, the air passingfrom the cooling means to the distributor will not be subjected toatmospheric temperatureexisting on the outside of the connection andwill, therefore, berelatively .cool when .it reaches the distributor.

apertures for emitting the cool air, the combined area of which isconsiderably in excess of the area of the conection to the distributor,the" force of the air leaving it is greatly diminished so that the airdescends within the enclosure principally by virtue of its "loweredtemperature,

As numerous changcs may beapparent to those a. 7 skilledin the art,my'invention is not limited to the single illustration, but is definedin the terms of the appended claims.

I claim:

1. In an air conditioning system, in combination, an enclosure forsurrounding a portion of a bed and formed of a top wall and side walls,an outlet conduit connected to said enclosure for conducting air fromwithin the enclosure, air conditioning means connected to said conduitand being operative to continuously withdraw and cool the air fromwithin said enclosure, an air distributor consisting of a shallow membersupported within the interior of the enclosure beneath the top wall andextending over the major portion of the interior of the enclosure andhaving its outer edges spaced inwardly from the side walls, the lowersurface of said distributor hav ing a plurality of substantiallyregularly spaced openings, a second conduit connecting said airconditioning means and said distributor to return conditioned air tothe'interior of said enclosure, said second conduit having an openingtherein which is spaced beneath and at one side of the lower surface ofthe air distributor, and a damper associated with the opening in saidsecond conduit for venting a portion of return air from said secondconduit in a substantially lateral direction with respect to theopenings in the lower surface of the air distributor.

2. In an air conditioning system, in combination, an enclosure forsurrounding a portion of a bed and formed of a top wall and side walls,air conditioning means for supplying cooled conditioned air to theinterior of said enclosure, and an air distributor consisting of ashallow member wholly contained within the interior of the enclosurebeneath the top wall, said distributor having an inlet opening connectedto said air conditioning means for receiving cooled conditioned air, thelower surface of said distributor having a multiplicity of smallsubstantially regularly spaced outlet openings, the total area of theoutlet openings being substantially greater than the area of the inletopening to reduce to substantially nil the velocity of air leaving thedistributor, said distributor extending over the major portion of theinterior of the enclosure and having its outer edges spaced inwardlyfrom the side walls of the enclosure, whereby the cooled conditioned airleaving the distributor forms a quiescent descending column within acentral area of the enclosure.

3. In an air conditioning system, in combination, an enclosure forsurrounding a portion of a bed and formed of a top wall and side walls,an air distributor consisting of a shallow member supported beneath thetop wall and extending over the major portion of the interior of theenclosure and having its lateral edges spaced inwardly from the sidewalls, the lower surface of said distributor having a multiplicity ofsubstantially regularly spaced outlet openings for distributing airdownwardly within the enclosure, said distributor having an inletopening, air cooling means positioned in close relationship to theenclosure and having an outlet opening for cooled air extending in thedirection of a side wall of the enclosure, and a conduit extendingthrough the side wall of the'enclosure and connecting the outlet openingof the air cooling means with the inlet opening in said distributor,said conduit having substantially its entire linear portion within theenclosure and in contact with the cooled air passing from the entirelinear portion within the enclosure and in contact with the cooled airpassing from the distributor to minimize the gain in temperature of thecooled air as it passes from the air cooling means to the distributor.

4. In combination with an enclosure including side walls adapted tosurround a portion of the bed, a top secured to the side walls, anoutlet conduit connected to said enclosure for with- 10 drawing airadjacent an upper peripheral portion of the top of said enclosure, airconditioning means connected to said conduit and being operative tocontinuously withdraw and cool the air within said enclosure, and an airdistributor sup- 5 ported by the top and wholly contained within theinterior of the enclosure and connected to said air conditioning meansto return cooled air to said enclosure, the peripheral limits of saiddistributor being spaced inwardly from the side walls of the enclosure,said distributor having an inlet opening and a multiplicity ofdownwardly projecting outlet openings, the combined area of the outletopenings being substantially greater than the area of the inlet openingso that the 5 cooled air leaving the distributor is in a quiescentcondition and is spaced inwardly from the side walls of the enclosure toform a central descending column that displaces the air within thecentral part of the enclosure and causes the same to rise in the form ofan annulus surrounding the descending column and extending continuouslybetween the descending column and the surrounding walls of theenclosure.

5. In an air conditioning system, in combination, a hood having a top, aflexible fabric curtain formed of material having a relatively high heattransfer capacity depending from the top and adapted to surround aportion of a bed, a conduit extending from a source of cooled air and 0penetrating the fabric curtain, a hollow box-like air distributor whollycontained within the fabric curtain and supported by the top, theperipheral limits of said air distributor being spaced inwardly from thefabric curtain, said distributor 5 being connected to the other end ofsaid conduit, said distributor having a multiplicity of small openingsin its lower surface, the total area of said openings beingsubstantially less than the area of a cross dimension of the conduit forreducing to substantially nil the velocity of air leaving thedistributor, whereby the cooled air descends in a central column withinthe interior of the fabric curtain, and a controlable opening in saidconduit within the interior of the fabric curtain for directing aportion of the cooled air into contact with the descending centralcolumn to agitate the air within said enclosure.

JAY A. I-IEIDBRINK.

REFERENCES orrnn The following references are of record in the file ofthis patent:

UNITED STATES PATENTS 15 2,310,222 Deverall Feb. 9, 1943

